HARRISBURG — Gov. Tom Corbett has dismissed another education secretary, the second in three months. Corbett’s office said today the governor has asked for and received the resignation of his nominee for the job, William Harner, less than three months after he started. Corbett’s office did not explain the move. Harner said earlier today as he was walking into the Capitol that he knew nothing about his nomination potentially being withdrawn and that he expected to be confirmed by the Senate next month. The upheaval at a major agency comes as Corbett gears up for re-election. Harner, a retired Army officer, had previously served as the superintendent of the Cumberland Valley School District, a large suburban Harrisburg school district. He replaced Ron Tomalis on June 1.